10 Cool Things About Carl Sagan

Carl Sagan and his wife author Ann Druyan pose in the Turnbull Conference Center on the campus of Florida State University in Tallahassee, Fla. in 1984. Mickey Adair/Getty Images

It was the summer of 1977, and Carl Sagan's newest brainchild was coming to life. For months, he and Ann Druyan -- a writer and producer working as the Voyager recording's creative director -- had been amassing a very special collection. They were creating a cosmic mix tape, a recorded greeting for the universe that would be dispatched with the Voyager 1 and Voyager 2 space missions.

But it wasn't until Druyan discovered just the right Chinese melody -- a 2,500-year-old song called "Flowing Stream -- that she and Sagan discovered their love for each other. Thrilled with her find, Druyan telephoned Sagan with the news, but was forced to leave a message. When he returned her call, they were on the phone for an hour. And by the time they said their goodbyes, they were engaged to be married -- with nary a first date between them.

The sensation of falling in love was so strong, Druyan had the electrical impulses of her brain and nervous system recorded so that it could be turned into music and placed on the Voyagers' recorded greeting when the spacecraft were launched into space on Aug. 20, 1977.

In 1981, Sagan and Druyan were married, and remained together until Sagan's death 15 years later [source: Krulwich].